1. Field of the Invention
The present invention relates to the art of electrical connectors. In detail, the present invention relates to a central processing unit (CPU) socket, and more particularly to a socket that has an insulative housing with contact retaining structure.
2. Background of the Invention
Electrical connection between two terminals is generally facilitated by normal force exerted from one terminal to the other. However, since surface of the terminal could be contaminated by dust or oxidation, it is preferable to generate a wiping displacement between two terminals during mating. With the wiping displacement between the terminals, dust or oxidation on the terminal could be wiped out, thereby ensuring reliable electrical connection between two mated terminals.
U.S. Pat. No. 5,244,396 issued to Matsuoka on Sep. 13, 1993 discloses an arrangement for electrical connector in which contact 9 is obliquely arranged and which may provide a wiping displacement between contact 9 and element 4. However, Matsuoka's device is too complicated to implement.
In Matsuoka device, element 11 is insert molded within element 1, while contact 9 is moveably arranged within the element 11. The contact 9 includes a pair of arms 8 which can be deformed when the contact 9 is pushed downwardly by element 4. As stated above, the Matsuoka device is too complicated to be implemented in the socket connector for used with a CPU. (U.S. Pat. No. 6,083,022 discloses another oblique arrangement of the contacts in the connector housing.
U.S. Pat. No. 5,820,389 issued to Hashiguchi on Oct. 13, 1998, discloses an electrical connector to be used between a printed circuit board and a LSI (Large Scale Integration) circuit of the type which is disclosed in Japanese Utility Model Publication (B) No. 13191/1995 (hereinafter referred to as the '191 Publication). Since the '191 device can not provide enough wiping displacement between the contacting end and a corresponding conductive pad, Hashiguchi (the '389 patent) then provides an improvement on the arrangement of the contact such that a contact end thereof may perform an effective wiping displacement over a corresponding pad to ensure an effective electrical connection.
As shown in FIGS. 9A, 9B and 9C, the contact 20 is arranged in a passageway formed vertically in the housing 10. The contact 20 includes an extension 24 having a free end 24b. Theoretically, when contact end 23a is depressed by the element 200, contact end 24b will displace from its original position. It is understandable that Hashiguchi device is better than the '191 device as the extension 24 displace more than that of the '191 device. However, since the contact 20 is vertically arranged within the passageway, it is unlikely that the contact end 23a to perform a wiping displacement with respect to the corresponding element 200. Understandably, Hashiguchi solves only portion of the problem encountered by the '191.
On the other hand, even the extension 24 is arranged obliquely, the wiping displacement conducted by the contact end 24b is still not enough since before the contact end 24b is moved when the portion 23a is moved vertically down, there is a deformation incurred in portion 21a. Accordingly, Hashiguchi still leaves an opening for further improvement.
By the way, Hashiguchi does not meet the requirement since only the contact end 24b displaces a short distance over a conductive pad, while the contact end 23 does not displace when it is contacting with corresponding conductive pad.
U.S. Pat. No. 6,447,304 issued to Korsunsky discloses a first electrical device similar to the above described, and includes a first substrate having at least a first conductive pad formed thereon. A second electrical device includes a second substrate having at least a second conductive pad formed thereon. An electrical device is arranged between first and second electrical devices for electrically connecting the first and second conductive pads of the first and second electrical devices. The electrical device includes a housing defining at least a passageway extending between first and second surfaces. At least an electrical contact is moveably installed within the passageway with contacting ends extend beyond the surfaces. However, Matsuoka's device is too complicated to implement.
Therefore, there is a heretofore unaddressed need in the industry to address the aforementioned deficiencies and inadequacies.